Partnering to reduce emissions through technology.

While much of the global focus is on decarbonising the aluminium smelting sector, the emissions associated with the mining of bauxite and refining of alumina are not being forgotten. Australia has more than 50 years of technical experience in bauxite mining and alumina refining technologies.

This experience helps not only us, but our bauxite, alumina and aluminium customers, to reach their sustainability goals. Alcoa, Rio Tinto and South32’s Worsley Alumina operations all have their global research headquarters in Australia, helping develop new technologies for the world.

Australian bauxite and alumina will help meet global demand for aluminium

Australia is the world’s largest producer of bauxite, mining more than 100Mtof bauxite a year, or about a quarter, of global production. About 40% of this is
exported and 60% is turned into alumina here in Australia. We are the world’s
second largest producer and largest exporter of alumina, with production of
more than 20Mt a year. Of this, about 85% is exported and the remaining 15%
is turned into aluminium at the nation’s four smelters. Meeting the continued and
increasing global demand for primary aluminium will require proportionate
increases in production of bauxite and alumina.

Australia’s alumina already has some of the lowest emissions in the world, with an
average emissions intensity of 0.7 tonnes of carbon dioxide per tonne of alumina (t
CO2-e/t), compared to the global industry average of 1.2 tCO2-e/t. However, as a
large producer and exporter, alumina

Helping develop low carbon alumina mining and refining technologies for the world

In 2021, the members of the Australian industry announced a number of key strategic partnerships to trial and commercialise key decarbonisation technologies within mining and refining operations. Also in 2021, the Australian Aluminium Council welcomed four new members, including South32’s Worsley Alumina operations, made up of its bauxite mine and alumina refinery. South 32’s membership means the Council now represents all five of Australia’s major bauxite mines and all six of its alumina refineries. Having the full value chain of Australia’s major producers collectively represented strengthens the industry’s domestic and global voice on key policy issues, including decarbonisation.

Aluminium smelters are already electrified, so no technological conversion is required to enable them to run on renewable electricity, or a grid mixed with variable renewables, providing the electricity is supplied consistently with firm power. By contrast, alumina refineries have, to date, used thermal energy derived from gas, coal and fuel oil, supplemented by electricity.

Alumina refining is an energy intensive process, using about 10.5 GJ / t alumina produced. Digestion and calcination are the two most energy-intensive steps, with digestion consuming around two thirds of this energy. All of Australia’s alumina refineries have some combined heat and power generation (cogeneration) facilities which use a combination of coal, gas, or biomass fuels. This cogeneration results in the refineries using, and in some circumstances where the co-generation is large scale, exporting low emissions electricity. About 5-10% of an alumina refinery’s energy is used in electrically driven pumps, fans and conveyors.

Beyond Mining and Refining

In addition to looking at bauxite and alumina specific technologies, the Australian Aluminium Council and its members are working across major industry to help accelerate the development of technologies which may have multiple applications in the transformational change required to achieve net zero emissions.

In June 2021, the Australian Government announced a ten-year partnership arrangement with the Heavy Industry Low-carbon Transition Cooperative Research Centre (HILT CRC). The Council, Alcoa, South32 and Rio Tinto are all partners in the HILT CRC which focuses not only on alumina but also on iron, steel, cement, lime, hydrogen and ammonia. Australia has a unique opportunity to leverage the critical clustering of skills, resources and energy demand in the regions in which alumina refineries and aluminium smelters are located. Partnering across industries provides a framework for industry to collaborate, sharing knowledge and experience while lowering the risk of trialling technology.

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